A-P HA transfer to auxiliary node failed...

Dear All,

Our customer configured A-P HA, firmware 16.01.2.

After the active node transfer to auxiliary node with unknow reason, there are many services become unregistered.

Such as ipsec, sslvpn, pptp, dhcp,... services.

How do I restart these services manually?

And why the A-P HA transfer make these services failed?

If the transfer will make services failed, how to ask user to buy 2 XG nodes for HA? 

Is there a way to check the all needed services are all right for user?

Thanks.

PS. 
Our customer changed the active node back and the services worked well finally.